Standard-Duty Underpinning Brackets for Helical Pile Foundation System For use with 1 1/2″ and 1 3/4″ square shaft anchors, as specified below, each bracket is identified by the size stamped on the vertical gusset. Brackets also may be used in conjunction with Uplift-Restraint Bracket. Bracket comes complete with the hardware required for assembly of bracket; does not include concrete anchor bolts.